366 ENGINEERING ON THE FARM 



no reservoir space, in order to furnish a sufficient supply of 

 water it is necessary that an open water-bearing stratum 

 be reached such that the water will flow into the bottom of 

 the tube as rapidly as it is taken out by the pump. Such a 

 condition can usually be determined by means of water 

 poured into the top of the tube. If the tube cannot be 

 filled, it is a fairly good indication that there is a free flow in 

 the water stratum. 



Pumps. The ordinary lift pump which may be had in 

 the cast-iron stock is adapted to all types of wells. The size 

 of pipe used is i% and i}4. inches. The stock and cylinder, 

 with about 3 feet of pipe, are included in the regular list 

 price. The size of cylinder used will depend upon the height 

 that the water must be lifted. By the use of the figure 

 . 43 of a pound per square inch of area of the plunger for 

 each foot that the water must be raised, the total power 

 required may be determined. The number of strokes per 

 minute which a pump plunger may make is limited by a 

 piston travel of about 100 feet per minute. 



The market offers three types of pump cylinders: cast- 

 iron, cast-iron with brass lining, and a solid brass shell. 

 The cast-iron is the cheapest, and is only about half as 

 efficient as the brass or the brass-lined. The virtue of the 

 brass cylinder is that it does not corrode and roughen. 

 With any variety of water storage, it becomes necessary to 

 use a force pump. Such pumps usually have a longer stroke 

 than the ordinary lift pump. They also have provision for 

 diverting the water at a point several feet below the ground 

 surface. This does away with the danger of freezing. The 

 efficiency of the pump cylinder is seldom more than 50 or 

 60 per cent. The height that a pump will draw or suck 

 water is limited to about 20 feet. If the pump were 100 per 

 cent efficient, it would be able to draw it about 34 feet. 

 The height to which a pump may lift water is limited only 

 by the strength of the materials used in cylinder, plunger, 

 and pipes, together with the power available. A gas engine 



